1. Field of the Invention
The present invention relates to a cord cutter head for use in, for example, a grass trimmer.
2. Description of the Prior Art
In general, a cutter head has a flexible cord made of a plastic such as nylon and adapted to serve as a cutter blade. The cord cutter head also has a housing fixed to one end of a drive shaft, and a spool accommodated by the housing and carrying the cutter cord wound thereon. In operation, the free end of the cutter cord is extracted by a desired length. The drive shaft is drivingly connected to a suitable power source such as a small-sized internal combustion engine, through a suitable transmission.
When the cutter cord outside the housing has been worn out or cut accidentally, it is necessary to extract a new portion of the cutter cord from the housing. Hithereto, the extraction of the new portion of the cutter head is conducted semi-automatically by means of, for example, a device generally referred to as "inertia shifter".
Such a conventional cord cutter head, however, suffers from a disadvantage in that the construction is complicated and the size is increased with a result that the weight and the cost are increased undesirably. In addition, handling and operations, as well as repair and maintenance, are generally difficult to conduct.